These cars were once a common sight on Britain’s roads but now their numbers are dwindling.

According to tracking app ‘How Many Left’, some once-common models like Mini Metros and Morris Marina are now so rare they are on the verge of extinction.

The once mighty Ford Sierra is another car which is vanishing from our roads, with 64,000 of the 80s and 90s staple disappearing in the last decade. Now, just 1% of the 3.5m Sierras that were produced remain active.

British-made Ford Cortinas are another model which could be soon consigned to the history books and scrap yards.

Here are the top 10 rarest mass produced motors, according to How Many Left.

Austin Maxi 1969-81

Austin Maxi (Image: Hulton Archive)

It seems the jury’s out on this 1970s classic. Some say it was ahead of its time with its flexible, spacious layout and fifth gear but it had quality issues. Essentially a scaled-up Mini with loads of space and a practical hatchback, it is not remembered with universal fondness, says cargears.net. Production totalled 472,098.

There were 318 left in 2005. Only 159 remain.

Austin Allegro 1973-82

Austin Allegro

The bronze medal goes to the Allegro, the car that has come to symbolise all that was wrong with 1970s Britain. Launched in 1973 with its now-infamous quartic (or square) steering wheel, it became known as “the worst car of all time”. To others it was the epitome of kitsch. One company hired them out to do “ironic” Cotswold tours. Of the 642,340 built, only 186 survive today.

Vauxhall Chevette 1975-84

Vauxhall Chevette

Incredibly ugly, the Chevette was sold as a three-door hatchback or estate.

It was Vauxhall’s take on the T-Car small vehicle concept from its US parent General Motors. The family included the Opel Kadett in Germany and the Isuzu Gemini in Japan as the uncomprom­ising look spread around the world.

Only 232 of the 416,058 built are still on UK roads.

Hillman Avenger 1970-81

Hillman Avenger

Despite a production run of 638,631, only 229 survive.

Originally manufactured by the Rootes division of Chrysler Europe, it was later badged as the Chrysler Avenger and then manufactured by Peugeot as the Talbot Avenger.

It is now dubbed “the forgotten family car” of the 1970s.

Morris Marina 1971-80

Morris Marina (Image: Daily Mirror)

Despite being slammed as outdated, outclassed and a poor performer, the car’s lack of technical sophistication meant it was keenly priced.

It was the No2 UK best- seller in 1973 and was assembled with varying degrees of popularity around the world. More than 809,000 were built. In 2005, 550 were left. Now only 294 remain.

Ford Sierra 1982-93

Ford Sierra

It replaced the much-loved Cortina in 1982 and 3,470,524 were built up to 1993. There were 67,817 left in the UK in 2005 but that figure has plummeted to 3,900.

Vauxhall Victor 1957-76

Vaxhaul Victor

Although its recent rate of decline is not as alarming as that of the Sierra, which is disappearing despite selling in huge numbers, there are now only 829 Victors left, compared with 1,050 on the roads a decade earlier.

Mini Metro 1980-91

Mini Metro

More than 1.5 million were made but only 478 are now registered. The Metro, meant to replace the ageing Mini, limped on as the Rover 100 until 1999.

Ford Cortina 1962-82

Ford Cortina (Image: Getty)

Only 3,814 Cortinas remain of the 4,154,902 produced.

Not only was it Britain’s best-selling car in the late 1960s and 1970s, the saloon was also a hugely successful racing car.

A 1965 model raced by Sir Jackie Stewart is expected to make up to £120,000 when it goes under the auctioneer’s hammer at Goodwood racecourse, West Sussex, on March 18.

Painstakingly restored by its present owner, it carries the racing number 36, as it did in its heyday.

It has a black leather interior and a rebuilt engine from Ford of Germany.